Screw driver



J. A. SIGG SCREW DRIVER Filed Dec.

Nev. 25, 193d.

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Patented Nov. 25, 1930 PAT JosErn A. steer, or PITTSBURGH, rnivnsvfvnnm p scnnw nmvnn Application filed December 19.1929. Serial no". 415.238.

changeable blade holder embodying an adand with a hanjustable tube blade fastener, dlemem'ber formingan integral part thereof which is constructed as to contain therein extra blades of varying sizes.

Another object of the invention is to provide a screw driver comprising in combination a blade holder of the above designated character which embodies a friction tube blade fastener.

'Still another object of the invention is to provide ,a screw driver employing inter changeable blades in which the blades are formed to constitute a bi-bit or quadrate bit shape adapted for effective engagement with screw slots of varying widths and depths.

In the accompanying drawings constituting a part hereof and in which like reference characters designate like parts, Fig.1 is an elevational view of a screw driver embodying the principlesof this invention; Fig. 2 a sectional elevational view at right angles to the view of Fig. 1; Fig. 3 an elevational view of a modified form of screw driver with the handle portion partially in section and illustrating one form of the bit fastening means; Fig. 4- a sectional elevational View of the bottom part of Fig. 8 at right angles to Fig. 3; Fig. 5 an elevational View ofthe end of a screw driver illustrating another form of the bit fastening means; Fig.6 a similar view at right angles to Fig. 5; Fig. 7 a similar view to Fig. 6 of a modified form of fastening means; Figs. 8 and 9 end and side'elevational views respectively of one of the quadrate bits employed, and Fig. an enlarged detail of an end view partially in section taken along the lines X-X, Fig. 4;.

Figs. 1 and 2 of the drawings show a screw driver comprising a stem or blade holder 1 fitted into a handle member 2 by a ferrule 3 V in the usual manner. The stem 1 is provided with a. slotted opening 4 having a constricted portion?) at the bottom thereof and an enlarged circular portion 6. '50

A feature of this invention is to provide an OFF interchangeable quadratebit'blade 7 of Figs. i

8 and 9 andbi-bit blade 8 of Figs.- 5, 6 and 7 of complementary shape to the slotted porti'ons of Fig. l. *The blade 7 is provided at its center with a: convex portion 11, Figs. 8 and 9, to engage the portion 6 of slot 4. The quadrate blade 7, Fig. 8 andiFig'. 9, is

provided with 'four. bit ends 9 having paralleledges 10 shaped substantiallyas shown. In Figs. 5 and 6, ablade 8 has bi-bit ends 13 a with parallel edges 14-shaped substantially as shown with sides formed to engage the lugs ofthe locking deviceas hereindescribed. Another feature of'the invention resides in the means employed for holding theblades, with several modifications, as shown in the several figures of the; drawing. The blade holder 1, Figs. 1 andg2, isprovided. with grooves 15 in spacedrelationfor receiving curved keys "16 shaped substantially as shown, thetwo keys being provided to hold a sleeve 17- in a fixed axial-positionQ The. sleevel7 is internallythreaded at'18'and exa ternally knurled at 19. A locking device in the form --of a tube 20 .havinga slot 21 and externally threaded [portion 22 is disposed between sleeve 17 and holder 1 with its slot. 1

21 engaging the keys 16 and its threaded portion 22 co-actingwith the internal thread 18 ofsleevel'il I" if y 1 By rotatingthe sleeve 17 the tube-20 is given a longitudinal motion thus engaging the blade 7 inslot31 forming anabutment or seat in the lower end'of'the sleeve 20 and rigidly holding the blade in place as hereinafter described. The tube 20 may be reversed, end for end, so that the slot 23'shown by thedotted lines 2 1 will engage the keys16 and threads 25 will engage threads 18. I i

The tube 20, Figs. 5, 6 and 7 ,is cut and'slotted to form'two lugs 26 and 27 iI1itO Wl1l 0l11S placed a blade 8.formed toengagethe lugs. The blade is then drawn into slots 4and 5 by rotating sleeve 17 to engage the thread 25,

Fig. 2, of the tube 20 givingit a longitudinal motion until the bladeis rigidly held in place. Another modificationofthe invention is to holdthe blades 7 of Figs. 3 and 4 by means 7 of .an internal friction tube 28 adapted substantially as shown and *eXternallyknurled as at 29'. It will be seen that the tube 28 has a plurality of slots 30 at each end formed of varying sizes to fit over the varying sized bits of the blade 7 thus holding the blade rigid. The same slotting arrangement is placed in the end at 31 of the tube 20, Fig. 1, to substantially hold the blade 7 rigid.

In accordance with this invention there is provided a blade container 32 attached at 33 to the handle 2, Fig. 1, and forming a part of the handle. The container is suitably shaped with a slot 34 formed substantially as shown on two sides and said container is large enough to receive a number of bi-bit or quadrate bit blades, and acts as a repository thereof. Into the container is fitted a cap 35, Fig. 2, which is held by a spring 37 to its normal positions to fit over both of the slots. The cap is provided with a suitable finger grip 36 by means of which it may be withdrawn from the slots and the bits removed. The spring has the double function of maintaining the cap in its normal slot closing position as shown and returning the cap to this position when it has been pulled out of alinement with the slots to allow the removal and replacing of blades.

Fig. 3 is another modification showing a cored handle 39 with a cap 38 which may be formed of rubber, or other suitable material, with a cored center shown by lines 40 and 41. The cap is frictionally fitted in the handle substantially as shown by lines 42.

It is evident from the foregoing description of this invention that a screw driver made in accordance therewith may, by interchanging blades, be utilized on screws with varying sized widths and depths of slots without marring the screw slots It is further evident to those skilled in the art that various modifications may be made in the details of construction and in the arrangement of the several parts without departing from the principles herein set forth.

I claim herein as my invention:

1. A screw driver comprising a stem having a slotted end and a handle on its other end, said stem having a pair of radial lugs projecting in axially spaced relation, a sleeve nut disposed between said lugs and fixed against axial movement, an interchangeable bit disposed in the slotted end of said shank, and a sleeve adapted for screw thread engagement with said nut whereby it is subjected to axial movement on said shank to lock said bit in its operative position.

2. A screw driver comprising in combination a stem having a slotted end and having grooves on opposite sides of said slot, a bit having a blade portion the width of which corresponds to the diameter of said stem and having convex portions adapted to engage the grooves of said slot, a sleeve member on said stem and adapted to envelop a portion of said bit to retain it against lateral movement and means for holding said sleeve against the top of said bit to secure it in its operative position.

3. A screw driver comprising in combination a stem having a slotted end and having grooves on opposite sides of said slot, .a bit having convex portions for engagement with the grooves of said slot, a reversible sleeve having a slotted end for engagement with the blade of said bit when such blade is of greater overall width than said stem, and having its other end provided with extending lugs for engagement with slots in the bit when the latter is of the same width as the stem, and means for mounting said sleeve on the stem for movement in an axial direction to lock said bit in the slotted end thereof.

In testimony whereof I have hereunto set my hand this 17 day of December, 1929, at

Pittsburgh, Pa.

JOSEPH A. SIGG. 

